OpenPR stands for Open Pattern Recognition project and is intended to be an open source library for algorithms of image processing, computer vision, natural language processing, pattern recognition, machine learning and the related fields.

QPDF is a C++ library and set of programs that inspect and manipulate the structure of PDF files. It can encrypt and linearize files, expose the internals of a PDF file, and do many other operations useful to end users and PDF developers.

Re2c is a tool for writing very fast and very flexible scanners. Unlike any other such tool, re2c focuses on generating high efficient code for regular expression matching. As a result this allows a much broader range of use than any traditional lexer.